Interleukin-8 appears to be an important mediator of neutrophil function during inflammation and infection. Study of interleukin-8 in animal models has been difficult, however, because species specific monoclonal antibodies and recombinant IL-8 have not been available. Canine IL-8 has been identified and sequenced. Canine recombinant lL-8 and canine specific IL-8 monoclonal antibodies are now being developed. To better define the role of IL-8 in both the inflammatory injury as well as host defense of sepsis, we plan to collaborate with a biotechnology group developing canine specific IL-8. We will administer canine recombinant IL-8 in animals to determine the effects of this cytokine in vivo. More importantly, however, we plan to look at the effects of specific IL-8 inhibition in both canine peritonitis and pneumonia models.